Abstract:

Microstructure, physical, gelatinized and retrograded and thermal properties of sorghum starches from twenty varieties in China were investigated in this work. Most of the sorghum starches from twenty varieties selected in this study displayed irregular shape, concave surface and relatively bigger and uniform size of granules and some of them displayed honeycomb-like structure on the surface of granules; in contrast, the minority displayed spherical shape, smooth surface and relatively smaller size. Starch granular sizes from these varieties of sorghum ranged from 5 to 20μm. Physical, gelatinized and retrograded properties of sorghum starch exhibited remarkable differences among different varieties. Therefore, the choice of sorghum varieties should be different due to different processing purposes.

Key words: sorghum starch, microstructure, physical property, gelatinization, retrogradation, thermal property